Add a flag to struct pfs_vdata to mark the vnode as dead (e.g. process-

specific nodes when the process exits)

Move the vnode-cache-walking loop which was duplicated in pfs_exit() and
pfs_disable() into its own function, pfs_purge(), which looks for vnodes
marked as dead and / or belonging to the specified pfs_node and reclaims
them.  Note that this loop is still extremely inefficient.

Add a comment in pfs_vncache_alloc() explaining why we have to purge the
vnode from the vnode cache before returning, in case anyone should be
tempted to remove the call to cache_purge().

Move the special handling for pfstype_root nodes into pfs_fileno_alloc()
and pfs_fileno_free() (the root node's fileno must always be 2).  This
also fixes a bug where pfs_fileno_free() would reclaim the root node's
fileno, triggering a panic in the unr code, as that fileno was never
allocated from unr to begin with.

When destroying a pfs_node, release its fileno and purge it from the
vnode cache.  I wish we could put off the call to pfs_purge() until
after the entire tree had been destroyed, but then we'd have vnodes
referencing freed pfs nodes.  This probably doesn't matter while we're
still under Giant, but might become an issue later.

When destroying a pseudofs instance, destroy the tree before tearing
down the fileno allocator.

In pfs_mount(), acquire the mountpoint interlock when required.

MFC after:	3 weeks

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/fs/pseudofs/pseudofs.h b/sys/fs/pseudofs/pseudofs.h
index 49ba64a..bb1efd1 100644
--- a/sys/fs/pseudofs/pseudofs.h
+++ b/sys/fs/pseudofs/pseudofs.h
@@ -236,6 +236,7 @@ struct pfs_node	*pfs_create_link(struct pfs_node *parent, const char *name,
 				 pfs_vis_t vis, pfs_destroy_t destroy,
 				 int flags);
 struct pfs_node	*pfs_find_node	(struct pfs_node *parent, const char *name);
+void		 pfs_purge	(struct pfs_node *pn);
 int		 pfs_disable	(struct pfs_node *pn);
 int		 pfs_enable	(struct pfs_node *pn);
 int		 pfs_destroy	(struct pfs_node *pn);